The authoritative Hebrew text of the Tanakh (Jewish OT), preserved and transmitted by the Masoretes — Jewish scribes working primarily in Tiberias and Babylonia from about AD 500 to 1000. The Masoretes added vowel points (the written text had been consonantal only), accent marks, and elaborate marginal notes (Masorah) to preserve correct reading and guard against copyist error. The Aleppo Codex (c. AD 930) and the Leningrad Codex (AD 1008) are the two most important complete Masoretic manuscripts; the Biblia Hebraica Stuttgartensia (BHS) — the standard scholarly Hebrew Bible — is based on the Leningrad Codex.
The Masoretic Text's stability across centuries is one of the wonders of textual transmission. The Masoretes were meticulous to the point of obsession: they counted every letter of every book, noted the middle letter, preserved variant readings in the margins (Kethiv/Qere), and would destroy any scroll with a single error. When the Dead Sea Scrolls were discovered in 1947-1956 — pushing the earliest Hebrew manuscripts back by a thousand years from the medieval Masoretic manuscripts — scholars feared the new evidence might undermine the MT. The opposite happened. The Great Isaiah Scroll from Qumran (c. 125 BC) agrees with the MT Isaiah nearly word for word, with only minor spelling variants over 1,000 years of copying. This confirmed both the Masoretes' faithfulness and the reliability of the received Hebrew text. Differences between the MT and the Septuagint (Greek OT) are sometimes significant in specific places — the Jeremiah MT is 15% longer than the LXX Jeremiah, for instance — but the overwhelming textual core is stable. For the NT's OT quotations, readers should know that NT authors sometimes quote the MT, sometimes the LXX, and occasionally a form like neither — reflecting the textual plurality of first-century Judaism without undermining either.